Petra or Al-Batra inArabic is a historical and archaeological city in the southern Jordanian governorate of Ma'an that is famous for its rock-cut architecture and water conduit system. Another name for Petra is the Rose City due to the color of the stone out of which it is carved.
Established possibly as early as 312 BC as the capital city of the Nabataeans, it is a symbol of Jordan, as well as Jordan's most-visited tourist attraction.It lies on the slope of Jebel al-Madhbah (identified by some as the biblical Mount Hor) in a basin among the mountains which form the eastern flank of Arabah (Wadi Araba), the large valley running from the Dead Sea to the Gulf of Aqaba. Petra has been a UNESCO World Heritage Site since 1985.
The site remained unknown to the Western world until 1812, when it was introduced by Swiss explorer Johann Ludwig Burckhardt. It was described as "a rose-red city half as old as time" in a Newdigate Prize-winning poem by John William Burgon. UNESCO has described it as "one of the most precious cultural properties of man's cultural heritage"
Pliny the Elder and other writers identify Petra as the capital of the Nabataeans and the center of their caravan trade. Enclosed by towering rocks and watered by a perennial stream, Petra not only possessed the advantages of a fortress, but controlled the main commercial routes which passed through it to Gaza in the west, to Bosra and Damascus in the north, to Aqaba and Leuce Come on the Red Sea, and across the desert to the Persian Gulf.
Excavations have demonstrated that it was the ability of the Nabataeans to control the water supply that led to the rise of the desert city, creating an artificial oasis. The area is visited by flash floods and archaeological evidence demonstrates the Nabataeans controlled these floods by the use of dams, cisterns and water conduits. These innovations stored water for prolonged periods of drought, and enabled the city to prosper from its sale.
Today, most modern visitors approach the site from the east. The impressive eastern entrance leads steeply down through a dark, narrow gorge (in places only 3–4 m (9.8–13.1 ft) wide) called the Siq ("the shaft"), a natural geological feature formed from a deep split in the sandstone rocks and serving as a waterway flowing into Wadi Musa.
At the end of the narrow gorge stands Petra's most elaborate ruin, Al Khazneh (popularly known as and meaning "the Treasury"), hewn into the sandstone cliff. While remaining in remarkably preserved condition, the face of the structure is marked by hundreds of bullet holes made by the local Bedouin tribes that hoped to dislodge riches that were once rumored to be hidden within it.
A little farther from the Treasury, at the foot of the mountain called en-Nejr, is a massive theatre, positioned so as to bring the greatest number of tombs within view. At the point where the valley opens out into the plain, the site of the city is revealed with striking effect. The amphitheatre has been cut into the hillside and into several of the tombs during its construction. Rectangular gaps in the seating are still visible. Almost enclosing it on three sides are rose-colored mountain walls, divided into groups by deep fissures and lined with knobs cut.
Petra declined rapidly under Roman rule, in large part from the revision of sea-based trade routes. In 363 an earthquake destroyed many buildings, and crippled the vital water management system. The last inhabitants abandoned the city (further weakened by another major earthquake in 551) when the Arabs conquered the region in 663. The ruins of Petra were an object of curiosity in the Middle Ages and were visited by Sultan Baibars of Egypt towards the end of the 13th century. The first European to describe them was Swiss traveller Johann Ludwig Burckhardt in 1812.